iio: adc: rockchip_saradc: add saradc support for rk3399

The ADC is a 6-channel signal-ended 10-bit Successive
Approximation Register (SAR) A/D Converter.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2 files changed